Ice rink cover

ABSTRACT

A load bearing, thermally insulating panel for use to cover an ice surface is made up of a plurality of modular, polymeric floor members having a structural dense body structure and a flat upper wall over which a vehicle can travel. Each floor member has an undersurface with integral, downwardly projecting, load distributing, support pillars within a floor member-surrounding, downwardly projecting marginal wall. A polymeric foam insulative layer of substantially lesser density than said floor member and substantially lesser thermal conductivity is molded within the floor member surface surrounding the pillars to fill the space around the pillars and the space between the pillars and marginal wall.

This application is a division of application Ser. No. 08/762,425, filedDec. 9, 1996, now U.S. Pat. No. 5,820,798, issued Oct. 13, 1998, andclaims the priority of provisional application Ser. No. 60/014,913,filed Apr. 5, 1996.

This invention relates to rigid cover modules which can be assembled toform a cover for ice surfaces which primarily are used in multipurposesports event centers for the purposes of team hockey, figure skating andopen skating. Such centers are normally constructed with a refrigerantsystem grid of galvanized piping under a permanent concrete floor forthe circulation of a continuous flow of a refrigerant of thehydrochlorofluorocarbon variety or the hydrofluorocarbon variety. Sinceit will be normally imperative to use the center for other non-icesurface sports and events, it is necessary that the ice be maintainedwith some type of thermal cover which permits the facility to stage orproduce other events on top of the ice floor.

One of the cover products in use today for this purpose is a thermalblanket sold under the mark Homosote which is believed to be groundpaper, pressed into sheet configuration, which is used as a packagingmaterial and in building construction for sound insulation. When used asan ice floor cover, it is applied in 4×8 foot panels with thicknessesranging from 1/2 inch to 11/2 inch. It has a relatively short life spanand grows in volume as it undesirably absorbs moisture. It furtherleaves residue on the ice surface requiring deeper scraping of the icemachine when the ice surface is again to be exposed and used. Othershave used plywood, laminated board, particle board, pressboard, masoniteand cardboard covers, but covers of this type, which often have beenconstructed by the building managers, are of limited durability, lowinsulative value, sweat in humid conditions, can create a storageproblem, are not very crush resistent when utilizing foam as a thermalcore, and are relatively expensive.

Other prior art systems include a NorCore product, which is a plastichoneycomb product with ABS skins laminated to it, sold in 4×8 footmodules. This product is considered very expensive and appears to lackthermal resistance.

Still another product is the RinkTex cover, which is a rolled productsimilar to carpeting, which again is very expensive and extremely laborintensive in that it requires a trained crew to install and maintain.

Still a further prior art product is known as the Cover master Cover,and comprises a series of extruded plastic strips which are hingedtogether so as to be able to roll up. The plastic strips have insertedfoam strips for thermal value but the crush resistance, slip resistance,low R-factor, handling and storage are problems.

Finally, another product, known as Terraplas material, is produced inone meter squares about 11/2" thick. This product, when used as a rinkcover, appears to lack sufficient structural integrity to supportrolling loads, and does not create the thermal barrier which we considerimperative.

SUMMARY OF THE INVENTION

The present invention is concerned with a cover which balancesinsulative value and crush and impact resistance. It is designed tosupport the fork lift trucks which are used to deliver and removebundles of the modules from the ice rink, as well as to support otherheavy equipment which is used for other sports and events when the coveris in place. It is normal for forklift trucks weighing 6,000 pounds andcarrying a load of 3,000 pounds to drive over such covers.

The invention is concerned with rink covers which are supplied inmodules and placed in abutting relationship to form an overall icecover. Each module is constructed with at least one structural plasticfloor frame which has mating load spreading support pillars arranged ina predesignated pattern and at predesignated intervals. The open areaaround and between the pillars, is completely filled with an insulativegenerally rigid foam material, to provide the necessary insulativevalue, while at the same time assisting in providing the requisitecompressive and impact strength. The foam material occupies 85-95% ofthe space within the floor relative to the pillars in the embodimentsdisclosed.

It is a prime object of the present invention to achieve a predeterminedbalance between the insulative value and the crush and impact resistanceof the module panel to provide a product which can successfully beutilized for the designated purpose.

Another object of the invention is to provide a product which can bereadily handled, and which is cuttable so that the panels can becontoured to the perimetral contour of the ice arena where this isnecessary.

Another important object of the invention is to provide a product whichdoes not absorb moisture, does not freeze to the ice during temperaturechanges, and leaves no residue on the ice which would create problemsduring ice scraping and in use.

Still a further object of the invention is to provide an ice cover whichis durable, which resists movement laterally on the ice surface, whichdoes not sweat in humid conditions, which can be relatively economicallyconstructed so that it can be marketed at reasonable cost, and which isreadily stored.

Other objects and advantages of the invention will become apparent withreference to the accompanying drawings and the accompanying descriptivematter.

THE DRAWINGS

Several embodiments of the invention are disclosed in the followingdescription and in the accompanying drawings, wherein:

FIG. 1 is a perspective elevational fragmentary view of an ice rinkcover formed by positioning the modules of the cover in abuttingrelationship;

FIG. 2 is a considerably enlarged perspective elevational view of one ofthe panel modules only;

FIG. 3 is a fragmentary vertical section through one of the modules;

FIG. 4 is an enlarged fragmentary underside view of one of the modulehalves;

FIG. 5 is a schematic view illustrating steps utilized in the formationof the module;

FIG. 6 is an underplan view of the module of a modified embodiment ofthe invention;

FIG. 7 is an edge elevational view of the module of FIG. 6;

FIG. 8 is an enlarged, fragmentary sectional elevational view taken onthe lines 8--8 of FIG. 6;

FIG. 9 is an enlarged, fragmentary sectional elevational view taken onthe lines 9--9 of FIG. 6 but omitting the foam filler; and

FIG. 10 is a greatly enlarged, fragmentary view similar to FIG. 9 withone of the movement resisting insert members in place.

DESCRIPTION OF ONE EMBODIMENT

Referring now more particularly to FIG. 1, first of all, it will be seenthat the rink cover, generally designated C, is comprised of a pluralityof individual modules or panels, generally designated M, which arearranged in abutting relationship. As FIGS. 2 and 3 more particularlyindicate, each module M is formed of an upper structural floor member,generally designated 10, and a lower structural floor member, generallydesignated 11. The polymeric floor members 10 and 11 are identical inconfiguration and preferably both are formed with a slip resistant outersurface, such as a pebble grain surface T, which provides traction onthe outer surfaces of the panel.

As shown, each of the horizontal floor portions 10c and 11c of thepanels 10 and 11 are formed with vertically extending perimetral edges10a and 11a, respectively, and with internal vertically extendingcylindrical pillars 12 and 13, respectively, which are in abuttingrelation throughout the panel. The panels 10 and 11 may be formed in aconventional injection mold of a strong synthetic plastic using, what istermed in the trade, a "structural foam" injection molding process. Inthis process, an inert gas such as nitrogen is injected with the liquid(not foam), plastic injected, or is incorporated with the plastic andreleased in the mold to insure filling of the mold, and the rigid moldedproduct 10 or 11 formed has a cellular core with minute cells within animperforate outer skin. By weight, the product 10 or 11 will be 85%-90%resin. While the polyolefins and, particularly, high densitypolypropylene and high density polyethylene are preferred as thestructural plastic, it is thought that other plastics such as nylon orABS and others, would be suitable, from a strength consideration.

It will be noted that the pillars 12 and 13 in the first embodimentdisclosed are heat welded together at a bead 14 which is formed at theirend abutting surfaces, and floors 10 and 11 are also integrated at aperimetral bead 15 formed between the edge walls 10a and 11a. The matingpillars 12 and 13 are solid, not tubular, and may be arranged at apredetermined spacing and in an overall pattern which provides therequisite compressive strength. For instance, the pillars or posts 12and 13 are substantially 1/4" in diameter and spaced center to center at1" intervals in horizontal and transverse rows 16 and 17, as shown inFIG. 4. The floors 10c and 11c and floor edge walls 10a and 10b, and 11aand 11b, are substantially 1/4" in thickness.

The floor halves 10 and 11 are molded with finger tip lifting slots,generally designated 18, formed when the vertically extendingperimetrally continuous edges 10a and 11a are inset at intervals, as at10b and 11b, inward of the corners of the module, as shown in FIG. 4, toprovide a series of hand holds 18 in each side edge of the module. Thisinsetting of portions of the abutting edges 10a and 11a leaves outwardlyprojecting portions 19 of the thickness of the interior floor portions10c of the half 10, and 11c of the half 11. The interior of the abuttingupper and lower side sections 10a and 11a is, however, sealed offbecause the portions 10b and 11b of the vertically extending edges 10aand 11a, are continuous with the edges 10a and 11a, and heat weldedtogether in the same manner.

Provided to completely fill the remaining interior of the panel sections10 and 11 is a substantially rigid, polymeric foam insulation 20 whichmay comprise a commercially available foam product which can be pressureinjected as a curable foam between the panel sections 10 and 11, oncethey are welded together, and which has the requisite R factor.Typically, the foam insulation 20, injected as a foam and not a liquid,may be a conventional polyurethane foam product but other plastics arecontemplated. Openings such as shown at 21 may be provided atappropriate places in the panel halves 10 and 11 and, after the foaminsulation 20 has been injected in a flowable state under pressurethrough them and allowed to cure in closed cell state, sealed with solidplugs 22.

It is important that the insulation foam cells trap air or gas toprovide the requisite insulative value. The insulative R value of eachentire module or panel M will be at least 1.98, and preferably greaterthan 2.5. Applicant has achieved an R factor of 2.79 with the moduledescribed, while incorporating the necessary strength.

In FIG. 5, one method of constructing the modular panel of FIGS. 1-4 ispartly schematically illustrated. As shown, the upper floor panel 10 isreceived in a fixture 22, carried by the platen 23 of a suitable press,while the lower panel 11 is held by a fixture 24 carried by the bed 25of the press. Provided between the floor members 10 and 11, is a heatedplate 26. The plate 26 can be mounted to move laterally into and out ofposition between the spread floor halves 10 and 11. When in place andthe floors 10 and 11 are brought into abutting engagement with it, theplate will heat the perimetral edges 10a and 11a, and the cylindricalpillars 12 and 13, to a temperature which melts the surfaces which abutthe plate 26 to the melt temperature of the plastic. When these surfacesare sufficiently plastic and tacky, the plate 26 is removed and thepress members 23 and 25 are moved relatively to force the abuttingsurfaces of the floor halves 10 and 11 together under considerablepressure and form the beads 14 and 15. Typically, the thickness of theoverall module will be reduced by 0.015 thousandths during thiscompression and, of course, this is taken into consideration when thepanel halves 10 and 11 are molded in the first place. Each of the edges10a and 11a and the pillars 12 and 13 will be molded slightly oversizeby half of this increment to compensate.

The units 10 are believed to be considerably stronger when the edges 10aand 11a and pillars 12 and 13 are joined by heat welding than if, forexample, adhesive were somehow applied, because the panels 10 and 11will be made up solely of the same plastic without the introduction ofany other materials. The resistance to crush and the impact strengthcharacteristics are, of course, particularly significant in the midportions of the panels. Once the floors 10 and 11 are joined, theinsulating foam may be injected and allowed to cure in the mannerindicated.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now more particularly to FIGS. 6-10 of the drawings, wherein apreferred embodiment of the invention has been specifically disclosed,the rink cover, as before, is generally designated C, and is comprisedof individual modules or panels, generally designated M, which, aspreviously, are arranged in laterally abutting relationship. Because themodules to be described resist displacement on the ice surface, thepreferred embodiment is particularly suited to use where only a portionof an ice surface is to be covered. Whereas, previously, a pair of floormembers were provided in vertically abutting relationship, the presentembodiment incorporates only the upper floor member 10, which still isformed with the slip resistent outer surface, such as a pebble grainsurface, as previously, to provide traction.

The floor portion 10c of the panel 10, which is shown in invertedposition in FIGS. 6-8, is formed with vertically extending perimetraledges boa and integral, internal, vertically extending solid cylindricalpillars 12. The substantially solid, tough panel 10 is, as previously,formed in a conventional injection mold of a strong synthetic plastic ofthe character earlier described, injected as a non-expanded liquid, andthe pillars 12 are solid and rigid, not tubular, and are arranged with apre-determined spacing, and in an overall pattern, which provide therequisite load distribution and compressive strength. The floorthickness 10c typically will be 1/4" and the pillars 12 and edge walls10a will be 11/2". The pillars 12, at their juncture with the floor 10c,have a diameter of typically 1/4" and at their upper ends have adiameter typically of 0.234". The side wall 10a typically will have athickness of 1/4". The pillars 12, further, typically merge with thefloor 10c along fillets which have a radius of 0.12". Typically, thepillars 12 will be spaced apart a distance of one inch, center to centerin FIG. 8.

As previously, the floor 10 is molded with the finger tip lifting slot18 which is constructed in the same manner as previously described, andhas projecting grasping portions 19.

Provided to completely fill the interior of the self supporting, loadbearing structural plastic panel section 10, which remains unoccupied,is a foam insulation barrier 20 which cures as a closed cell,substantially rigid foam. This commercially available foam product isavailable from BASF Corporation under its designation Elastopor 12500-Rand from others. Particularly the foam insulation may be a conventionalpolyurethane foam product which is injected as a foam in an expandedflowable state under pressure and allowed to cure to substantialinelastic rigidity. The polyurethane foam will have a density of two tothree pounds per cubic foot in order to provide the requisite strengthand R factor. It will consist of closed cells which have trapped air toenhance the insulative value of this foam core and will have a smooth,non-porous, outer surface or skin 10d. In view of this, the module Mwill not pick up moisture and will not tend to freeze to the ice surfacewhich it engages.

FIGS. 6 and 9 indicate the placement and construction of pillars ofgreater girth 27 which in certain locations as shown in FIG. 6substitute for the pillars 12 and are provided with screw sockets 27afor the reception of oval head, stainless steel screws 28. The screws 28bite into the plastic material of the marginal walls of the openings orsockets 27a when they are threaded into a flush position on pillars 27.However, the oval heads 29 protrude as indicated in FIG. 10 to restrainsliding of the panel M on the ice during installation, and when notfully contained by a hockey dasher or rink side wall.

In this embodiment, the overall panel M thickness has been increased to11/2" and the thermal efficiency has been improved to reach an overall Rfactor of 3.81 or greater. In this calculation, which applies to thepanel M as an entire entity, the foam 20 itself has an R factor of about5, and is in the range 3 to 6 or greater. The molded structural floor10, preferably formed of a high molecular weight, high densitypolyethylene plastic with a lesser R factor of about 2.75 or greaterworks in combination with the foam core as a moisture barrier to providethe thermal efficiency required of this product. It will be of an almostcompletely rigid nature, as will the foam 20, but the overall coverpanels, while inelastic, will have sufficient flexibility to adapt toice surface unevenness when necessary. They, also, have a thermalinsulative capacity considerably greater than a metal top surface ofcomparable thickness, for example.

The modified polymeric modular panel is constructed somewhat differentlythan the double floor panel. In this method of manufacture, the floor10, which may be referred to as a "structural foam" molded product, isplaced in a fixture in inverted position and a metal platen, having itsinterior face covered with a release paper or agent, closes the openupper side of the floor panel 10. The foam core is sprayed in tocompletely fill the interior of floor 10 and occupy 85% of the spacesurrounded by the marginal edge, as previously, while the metal platenis being lowered into place, so it is not necessary to employ injectionports in the floor 10. The polymeric foam cures in a generally rigidclosed cell condition with a smooth skin 10d in the range of 10" to 20mils" in thickness on its exterior side which is flush with the free endsurfaces of pillars 12 and 27. Upon curing, it self adheres to the floor10 wherever it contacts floor 10. It is thought that the alternativematerials for the floor and core mentioned in connection with the firstembodiment enclosed might well be alternatively employed.

With the balance provided, of compressive strength and thermal barrierefficiency, fork truck traffic loads and castered equipment loads of 500pounds on 2" wide wheels, or 2,000 pounds on a four wheel cart, arereadily handled by the cover.

The disclosed embodiment is representative of a presently preferred formof the invention, but is intended to be illustrative rather thandefinitive thereof. The invention is defined in the claims.

I claim:
 1. An ice cover panel for use in covering an ice surface whichachieves a balance between strength in compression and thermalinsulative factor, comprising:(a) a polymeric floor member having adense structural body structure defined by a substantially flat upperwall surface over which a vehicle can travel and an undersurface; (b)said floor member undersurface having integral, downwardly projectingload distributing, discrete support pillars extending below saidundersurface within a floor member-surrounding, downwardly projectingmarginal wall extending below said undersurface, said floor member beingformed with space surrounding said pillars and space between saidpillars and marginal wall; and (c) a polymeric foam insulative layer ofsubstantially lesser density than said floor member, flowed into saidspaces and cured within the floor member marginal wall, to substantiallyfill the space around said pillars and the space between said pillarsand marginal wall and adhere to said pillars and marginal wall.
 2. Thepanel of claim 1 wherein said panel has a bottom surface defined bybottom surfaces on said pillars and marginal wall and the foam layer,which has a smooth surface unbroken bottom skin extending in a planeflush with said bottom surfaces of said pillars and marginal wall. 3.The panel of claim 1 wherein the foam occupies at least about 85% of thespace surrounded by said marginal wall.
 4. The panel of claim 1 whereina bottom floor member of the character defined in part (a) of claim 1 isthermally welded to the floor member defined in part (a) of claim 1 inan inverted position with its pillars and marginal wall in abuttingrelation with the pillars and marginal wall of the part (a) floor, andsaid bottom floor member is filled with the foam of part (b) of claim 1around its pillars and between its pillars and marginal edge.
 5. Thepanel of claim 4 wherein the foam occupies at least about 85% of thespace surrounded by the marginal wall of each floor member.
 6. The panelof claim 1 wherein said pillars cover said floor member and are spacedsubstantially on one inch centers, one from the other.
 7. The panel ofclaim 1 wherein said pillars at their lower ends are generally on theorder of a quarter inch in diameter, plus or minus.
 8. The panel ofclaim 1 wherein said marginal wall is laterally inset at spacedintervals below said floor upper wall surface to provide hand holdsurface portions.
 9. The panel of claim 1 wherein said pillars areslightly convergent and are filleted at their juncture with said floorupper wall undersurface.
 10. The panel of claim 1 wherein said floormember is formed of a high density polymer having minute closed cells.11. The panel of claim 10 in which said polymer is polyethylene havingat least an 85% resin content by weight.
 12. The cover panel of claim 1wherein said marginal wall extends downwardly substantiallyperpendicularly to said upper wall surface and comprises side and endwall portions which extend relatively perpendicularly.
 13. An ice coverpanel for use in covering an ice surface which achieves a balancebetween strength in compression and thermal insulative factor,comprising:(a) a modular, polymeric floor member having a densestructural body structure defined by a substantially flat upper wallsurface over which a vehicle can travel and an undersurface; (b) saidfloor member undersurface having integral, downwardly protecting loaddistributing, support pillars within a floor member-surrounding,downwardly protecting marginal wall, there being space around saidpillars and space between said pillars and marginal wall; and (c) apolymeric foam insulative layer of substantially lesser density thansaid floor member received on the floor member undersurface surroundingsaid pillars and substantially filling the space around said pillars andthe space between said pillars and marginal wall; and (d) certain widelyspaced pillars having inserts which protrude downwardly to resist panelslippage on the ice.
 14. The panel of claim 13 wherein certain widelyspaced pillars have screw openings receiving screws with screw headswhich protrude downwardly below said pillars and marginal wall.
 15. Adrive-over cover member having a bottom surface for contacting icesurfaces used for recreational and athletic purposes and the likecomprising:(a) a polymeric structural floor module member having a densebody structure with a substantially top flat wall surface over which avehicle can travel and a downwardly projecting floor member perimetralwall flange, the floor member flat wall having an under surface withintegrated, downwardly projecting load distributing support pillarswithin the floor member downwardly projecting perimetral wall flange,the floor member being molded with unoccupied space around said pillarsand unoccupied space between said pillars and perimetral wall flange,and said pillars and flange having substantially horizontally alignedbottom surfaces; and (b) a gas trapping, rigidly cured polymeric foaminsulative layer of substantially lesser density but substantiallygreater thermal insulative capacity than said floor member within saidperimetral wall flange substantially filling the said unoccupied spacearound said pillars and between said pillars and the marginal wallflange and having a bottom surface which terminates short of extendingbelow the bottom surfaces of said pillars and marginal wall flange; saidbottom surface of the cover member being formed by said bottom surfacesof said perimetral flange and pillars, and by said bottom surface ofsaid foam layer.
 16. The panel of claim 15 wherein said foam is asubstantially rigid foam having a density about or greater than twopounds per cubic foot, and the overall panel has an R value greater thanabout
 2. 17. The panel of claim 16 wherein the floor member has an Rvalue of about or greater than 2.75 and the foam layer has an R value ofabout or greater than
 3. 18. The cover member of claim 15 wherein saidfoam is a substantially rigid foam having a density greater than abouttwo pounds per cubic foot with an R value of about or greater than 5 andwherein the foam layer has a smooth unbroken non-porous bottom skin, andoccupies at least about 85% or more of the volumetric space surroundedby said marginal flange of the floor member while said pillars occupyabout 15% or less.
 19. The cover member of claim 15 wherein the floormember is constituted by a polymeric resin which by volume occupies atleast about 85% of the body structure.
 20. The cover member of claim 15wherein said floor member is molded of high density, minutely cellularpolyethylene and said insulative foam layer is formed in the floormember as a mold of a polyurethane foam which cures as a self-adhering,substantially rigid, closed cell foam, said foam layer having a smoothunbroken non-porous bottom skin extending flush with said bottom surfaceof said pillars and perimetral wall.